Trim Optimisation Introduction

Most ships are designed to carry a certain amount of cargo at a designated speed, consuming a certain amount of fuel under a specified trim condition. Loaded or ballast, trim has a significant influence on the resistance of the ship through water. Therefore, optimizing the trim can deliver significant savings. For any given draft and speed, there is a trim condition that gives minimum resistance. Therefore, the vessel optimum trim is a function of draft and speed. A ship’s optimum trim may be established as part of routine operations or through tank testing or use of computational methods. Nowadays, Computational Fluid Dynamics (CFD) methods are extensively used to estimate optimal trim settings for energy efficiency (MariEMS 2017).